The rise in obesity, now at epidemic levels in the United States, has been matched by a rise in diabetes, a deadly combination that increases heart disease risk by two to five times. Research has shown an association between obesity, insulin resistance and diabetes, and it is believed that insulin resistance plays an important role in the development of heart disease.
"Up to 80 per cent of obese people compensate for their insulin resistance by oversecreting insulin and therefore don't become diabetic. In the remaining 15-20 per cent, however, the pancreas is unable to compensate for insulin resistance and they become diabetic," said Temple University diabetes expert Guenther Boden, who has received a $1.9 million grant from the NIH for new research.
He added: "Over the years, we've determined that a major link between obesity and insulin resistance is a high level of free fatty acids. When the levels of free fatty acids circulating in the blood stream are too high, which is usually the case in obesity, they cause insulin resistance and seem to simultaneously set off inflammation. Inflammation may provide the missing link to heart disease."
The researchers will examine the inflammatory process, particularly what triggers it and what inhibits it. Previously, they demonstrated that in lean people, elevated free fatty acids cause insulin resistance and start the pro-inflammatory processes, which can in turn lead to heart disease. Now they will examine this phenomenon in more detail in obese patients.
"This is an exciting area of research. Cardiovascular disease is, to a large extent, an inflammatory process. For the first time, we're starting to understand why it is that being obese, diabetic and insulin resistant increases risk of atherosclerotic disease two-to-five-fold."
The research will look for the mechanisms involved in this process in a bid to improve knowledge to help prevent and treat heart disease in the millions of obese patients with diabetes.